I would like to fit a few TRV myself whilst the plumber fits a new boiler - obviously not when he is flushing the system 8-))) - I presume that he disconnects the old boiler, drains the system and starts to work on the boiler. I know that I could ask him to do it, but not only have I always wanted to try my luck with this, I am also keen to make savings wherever I reasonably can. A TRV from B&Q is only a fraction of the cost that he would charge me for the fitting. Needless to say I am not keen on messing up his job, or getting myself into trouble re boiler fitting and whatnot. In an ideal world, I would do this myself with the plumber unaware of what I am up to. Is that makeable, and if so, how to best do it.
Fred